間欠性外斜視手術の矯正効果に関連する術前因子および術式筋数の検討

Factors related to outcome of surgery for intermittent exotropia

要約　目的：間欠性外斜視の術後斜視角に影響する因子の検討。対象と方法：過去28か月間に初回手術を行った間欠性外斜視20例を対象とした。男性7例，女性13例で，平均年齢は11.5±10歳である。術式として，片眼の外直筋後転，片眼の前後転術，両眼の外直筋後転術，両眼の外直筋後転と片眼の内直筋短縮のいずれかを行った。斜視角の平均は35.4±10.8⊿であった。結果：術後3か月の最大斜視角と関連した因子は，立体視機能，術式，および1か月後の斜視角であった。術前の斜視角が40⊿以上の9例では，⊿/mmで評価する手術効果が，2筋に手術を受けた5例で，3筋に手術を受けた4例よりも有意に大きかった。結論：間欠性外斜視の術後斜視角に影響する最大の因子は，術前の立体視機能と手術を受けた筋数であった。

Abstract.　Purpose：To report factors related to the outcome of surgery for intermittent exotropia. Cases：This study was made on 20 cases who received surgery for intermittent exotropia during the past 28 months. The series comprised 7 males and 13 females. The age averaged 11.5±10 years. Patients received either recession of lateral rectus in one eye,recession-advancement of rectus muscles in one eye,recession of lateral rectus in both eyes,or recession of lateral rectus in both eyes with myectomy of medial rectus in one eye. Angle of strabismus averaged 35.4±10.8 ⊿. Results：Outcome 3 months after surgery was related with stereoacuity before surgery,surgical method,and angle of strabismus one month after surgery. In 9 patients who had deviation greater than 40 ⊿ before surgery,outcome of surgery as expressed by ⊿/mm was better in 5 cases who received surgery on 2 muscles than 4 cases who received surgery on 3 muscles. Conclusion：Outcome of surgery for intermittent exotropia is related to stereoacuity and surgical procedure.